The Proper ''Soomaal'' the name itself wasn't recorded until the Futuh (maybe it existed in older internal sources), but a pronunciation of it Semur/Simur was first mentioned in the Yeshaq poem who mentions it along side other clan names.
From it's earliest usage we can see that it wasn't an ethnic or a regional name , it was an local occupational name
Futuh al-Habasha: Somalis As Bedouins , so it explains the total absence of it in external sources by visitors despite the fact that they described Somalis in other ways that are recognizable
So i doubt Chinese who had no internal access to local names and breifly stopped at port towns would have mentioned it.
It's a no brainer why there is no mention of a Harari people in any of the medieval sources including Futuh.
Because Somalis never name themselves after towns, cities or settlements, there is no Zaylawis, Berberans , bosasan , mercans, luuqians, hobadians, the Mogadishans, Maydhians, Barians etc. There is no single group exclusively named from a toponym , instead you have usually ''Reer'' in front of it to indicate it ''The family from/of this''.
but Habeshas are different they will come down from other areas and appropriate the name/toponym of a place despite having zero locality or historical ties to it.
Researchers saw this with Argobba.
I don't think popali in the 9th century is Somalia, i mentioned this before in a different thread: They are lumping two seperate unrelated descriptions into one in those texts.
But this is one is an awsome find though it actually mentions Zayla as the center in the 8th century.
They even detail trade expeditions of Merchants of Zela visiting Guangzhou. Great stuff.